Update example on studies one openml issue 1005 is solved

[mfeurer]

Currently, it is not possible to search for a study which implements a suite. Once this functionality is offered by the OpenML server, we should update the study tutorial (caveat: this is not merged yet at the time of writing).

Reference issue: https://github.com/openml/OpenML/issues/1005

[mfeurer]

Example code should look like:

############################################################################
# In addition to a benchmarking suite one can also list only studies for a
# certain benchmarking suite, in this case the
# `OpenML-CC18 <https://arxiv.org/abs/1708.03731v2>`:
studies = openml.study.list_studies(
    output_format='dataframe',
    status='all',
    benchmark_suite=99,
)
print(studies.head(n=10))